How Your Heart Functions in Health and Disease

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How YourHeart Functions in Health and Disease
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Learning Points

• Overview of the heart and the circulatory system
• Causes of coronary artery disease (CAD)
• Risk factors for heart disease
• Angina and Heart Attack
• Treatment Options
• Future Trends

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The Anatomy and Function of the Heart
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The Circulatory System
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The Heart is a Pump

• Every 15 to 20 seconds, the heart circulates your
  entire blood volume of 4-5 L
• Contains four chambers separated into two sides
  (right and left)

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The Heart is a Pump

• The right side receives deoxygenated blood and
  pumps it to the lungs to be oxygenated
• The left side receives oxygenated blood from the
  lungs and pumps it out into the body

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• Two upper chambers called Atria
• Two lower chambers called Ventricles

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There are four valves

• Mitral valve
• Aortic valve
• Tricuspid valve
• Pulmonic valve

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Coronary Circulation

• The heart receives blood via coronary arteries
• The two main arteries are the right coronary
  artery and the left coronary artery
• The left coronary artery divides into the
  circumflex and the left anterior descending
  artery
• Collateral circulation may develop in response to
  coronary artery disease progression

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Cardiac Conduction

• The SA node is normally the pacemaker of the
  heart, firing at 60-100 times per minute
• Impulses originating from the SA node travel
  through the atria to the AV node
• Each impulse continues to travel through the AV
  node to the Bundle of His

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ECG Patterns
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Coronary Artery Disease
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Atherosclerosis

• The main cause is buildup of fatty plaques in the
  arteries (cholesterol, calcium, fibrin)
• This gradual buildup narrows the inside diameter
  of the coronary arteries
• Recent studies show that this process can start
  before birth
• May cause angina and can lead to a heart attack
• Collateral circulation may develop with time

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Risk Factors

• Modifiable
• Smoking
• High Blood Pressure
• Dislipidemia
• Inactivity

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Smoking

• Decreases available oxygen to heart muscle
• Raises blood pressure heart rate
• Contributes to coronary spasm
• Increases risk of blood clots
• Increases risk of having a fatal Heart Attack

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High Blood Pressure (Hypertension)

• Caused by several factors including stress, high
  salt diet, smoking and inherited factors
• Leads to artery wall damage and rupture
  (aneurysm)
• Leading cause of stroke, and heart disease
• Also known as theSilent Killer

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Blood Pressure Normal Values

• Systolic or top number should be lt140
• Diastolic or bottom number should be lt90
• Diabetics - should be lt130/80
• Several blood pressures must be taken to make a
  diagnosis of high blood pressure

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High Cholesterol

• High fat diet can interfere with normal liver
  function and increases cholesterol in the blood
• Family link
• Treatment with a low fat diet and exercise, Rx if
  needed

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Values for Cholesterol
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Lack of Regular Exercise

• Weakens the heart muscle
• Contributes to obesity
• 30-60 min. of aerobic activity recommended daily
• Walk, swim, bike

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Risk Factors

• Non modifiable
• Family History
• Age
• Gender
• Ethnic background

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Contributing Factors

• Overweight
• Stress
• High caffeine and alcohol intake
• Diabetes

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Angina (Chest Pain)

• Pain brought on by a transient lack of oxygen to
  the heart muscle which is a result of a narrowing
  in one of the coronary arteries
• Treated with nitro and rest

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Heart Attack Occurs

• Sudden onset of severe blockage in coronary
  artery stopping the blood flow to the heart
  muscle (blood clot at site of narrowed artery or
  plaque rupture)
• Coronary Artery spasm-- An involuntary closing of
  the walls of the artery. Usually occurs for a
  short period of time but can cause severe
  blockage
• May have coronary spasm and blood clot occurring
  together leading to a complete blockage

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Heart Attack Occurs
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Emergency Medical Interventions

• Aspirin
• Oxygen
• Nitro-spray
• Defibrillation

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Emergency Department

• ECG
• Bloodwork
• Interventions
• Clotbusters (Streptokinase or TPA)
• Heparin
• Angiogram (may lead to angioplasty)

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Diagnostic Testing

• Resting ECG
• Exercise stress test
• Echocardiogram
• Stress Thalium
• Angiogram

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Medical Treatment After a Heart Attack

• Medication to decrease the workload of the heart
• Low fat, low cholesterol diet
• Cadiac rehab
• education
• start an exercise program
• modify risk factors

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Long Term/ MaintenanceMedications
Different types of meds

• Cholesterol lowering agents
• Diuretics
• ACE inhibitors
• Beta blockers
• Nitrates
• Calcium Channel Blockers
• Anti-coagulants
• Digoxin

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Interventional Cardiology

• Angioplasty
• Stent
• Pacemaker

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Percutaneous Transluminal Coronary
Angioplasty(PTCA)

• Candidates for PTCA include patients with single
  and multivessel CAD lesions and documented
  myocardial ischemia
• The catheter is inserted in the arm or leg
• The catheter is passed through the diseased
  vessel and the balloon segment is positioned at
  the site of the blockage and inflated
• Blood-flow is then restored to underlying heart
  muscle

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Stent

• Is a wire mesh tube that is used to prop open an
  artery that has recently been cleared using
  angioplasty
• The stent is placed over the angioplasty balloon
  catheter
• When the balloon is inflated the stent expands,
  locks in place and forms a scaffold to hold the
  artery open

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Pacemaker

• Stimulates the heart to beart regularly by
  sending an electrical current to the heart
• The generator is the size of a silver dollar and
  is implanted just beneath the skin below the
  collarbone.
• The leads are threaded into position through
  veins leading back to the heart.

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Surgical

• CABG
• Valve Replacement
• Heart Transplantation

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Coronary Artery Bypass Graft(CABG)

• Provides a new supply of blood from the aorta to
  the native coronary artery beyond the site(s) of
  the blockage
• Indications are unstable angina that does not
  respond to medical treatment
• Stable angina with severe left-main or
  significant three-vessel coronary artery disease

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Valve Replacement

• Valves must flex, stretch, and hold back pressure
  to function normally.
• Aortic and Mitral valves are most commonly
  repaired or replaced.

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Heart Transplantation

• People who require heart transplants suffer from
  severe heart failure
• 2 major causes of heart failure are coronary
  artery disease (CAD) and cardiomyopathy

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Future Trends

• Primary prevention
• New medications
• Improvement and advancement in medical technology
• Angiogenesis and other genetic therapies
• Ongoing research to further identify risk factors

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Update in Current Research

• Researchers are continuing to investigate and
  identify additional factors that increase the
  risk for coronary artery disease.
• These additional markers include

1) Homocysteine 2) Lipoprotein (a) 3)
Fibrinogen 4) Plasminogen Activator Inhibitor - 1